In Arkansas Blue Cross & Blue Shield v. Doe, 22 Ark. App. 89, 733 S.W.2d 429 (1987), Doe was an insured under a group health policy issued by Blue Cross. After she was diagnosed with bipolar disorder, Blue Cross limited her benefits on the basis of a policy provision that restricted coverage for mental, nervous, or psychiatric conditions. Doe filed suit seeking coverage as if her condition were a physical illness. She presented evidence, mostly in the form of medical testimony, that her illness should be classified by cause rather than by symptoms and that the cause of her illness was biological. Blue Cross presented evidence that bipolar disorder should be classified as a mental disorder. The circuit judge, sitting as fact-finder, determined on the conflicting evidence that Doe's condition was physical rather than mental and thus ruled that Blue Cross's coverage restriction did not apply to Doe's bipolar disorder. On appeal, we upheld the judge's finding on the basis that it was not clearly against the preponderance of the evidence, and we gave due regard to his superior ability to judge the credibility of the witnesses.